---
title: "Materialize v0.39"
date: 2023-01-11
released: true
patch: 3
---

## v0.39.0

* Add `mz_internal.mz_source_statistics` to the system catalog. This table
  contains statistics for each process of each source in the system, like the
  number of messages and bytes received from the upstream external system.

* Add `mz_internal.mz_object_dependencies` to the system catalog. This table
  describes the dependency structure between all objects in Materialize. As an
  example, you can now get an overview of the relationship between user-defined
  objects using:

  ```mzsql
  SELECT
    object_id,
	o.name,
	o.type,
	referenced_object_id,
	ro.name,
	ro.type
  FROM mz_internal.mz_object_dependencies
  JOIN mz_objects o ON object_id = o.id
  JOIN mz_objects ro ON referenced_object_id = ro.id
  WHERE o.id LIKE 'u%' AND ro.id NOT LIKE 's%'
  ORDER BY o.name DESC, ro.name ASC;
  ```

  It's important to note that these tables are part of an unstable interface of
  Materialize (`mz_internal`), which means that their values may change at any
  time, and you should not rely on them for tasks like capacity planning for
  the time being.

* Add an `mz_version` system configuration parameter, which reports the
  Materialize version information. The value of this parameter is the same as
  the value returned by the existing `mz_version()` function, but the parameter
  form can be more convenient for downstream applications.

  ```mzsql
  SHOW mz_version;
  ```

  ```nofmt
         mz_version
   ---------------------
   v0.39.2 (e6af8921b)
  ```

* Automatically create a linked cluster associated with each source and sink.
  The mappings between sources/sinks and their respective linked cluster are
  exposed in the `mz_internal.mz_cluster_links` system catalog table.

  The concept of a linked cluster is not user-facing, and is intentionally
  undocumented. Linked clusters are meant to preserve the soon-to-be legacy
  interface for sizing sources and sinks, where a `SIZE` parameter is specified
  on the source/sink rather than the cluster replica.

* Add the `IDLE ARRANGEMENT MERGE EFFORT` advanced option to `CREATE CLUSTER
  REPLICA`, which enables configuring the amount of effort a replica exerts on
  compacting arrangements during idle periods.

* **Private preview.** Support [bearer token authentication](/integrations/websocket-api/#endpoint)
  in the WebSocket API endpoint, which supports interactive SQL queries over WebSockets.